Anhydrous Ammonia Release and Community Evacuation
Troy, Missouri
Facility and Industry Profile
The incident took place at the Lincoln County Farmers Co-Op on Highway J near Bobeen Lane in Troy, Missouri. This facility serves the regional agricultural sector by storing, blending, and distributing agricultural chemicals, fertilizers, and feed. A principal operation at this site involves the receipt and bulk storage of liquefied anhydrous ammonia under pressure, which is transferred into nurse tanks and application equipment for direct soil injection as a nitrogen fertilizer.
Incident Summary
On September 4, 2026, shortly before 6:00 a.m., an accidental release of anhydrous ammonia occurred during a transport unloading operation at the facility. A delivery truck driver was in the process of discharging product into a stationary bulk storage tank when containment was lost. The escaping ammonia expanded rapidly into a dense, ground-hugging vapor plume.
The City of Troy declared a State of Emergency. First responders initiated the evacuation of roughly 200 residences within a one-mile radius, encompassing the Meadowridge subdivision as well as homes along Excalibur Boulevard, Treasure Island Drive, and Hamlet Drive. Several schools in the Lincoln County School District were placed under shelter-in-place orders.
The delivery truck driver entered the vapor cloud to shut off the source without chemical protective gear or supplied-air respiratory protection. The driver sustained chemical exposure injuries and was transported to a local hospital. Responding emergency crews isolated the release by 7:50 a.m., and local authorities issued an all-clear notice at 8:12 a.m. after atmospheric monitoring indicated the plume had dissipated.
Speculation on Potential Factors
The initial loss of containment likely stemmed from a mechanical compromise in the transfer path, such as a failed transfer hose, a disengaged quick-connect coupler, or a burst connection gasket under line pressure (which typically runs between 100 psi and 200 psi for liquefied ammonia).
The fact that the driver manually re-entered the toxic cloud implies that remote manual actuators or automated emergency shutoff valves (ESVs) were either non-functional, absent, or located in an inaccessible position within the release zone.
If the leak rate was lower than the mechanical rating needed to trip the tank's internal excess flow valve, the valve would remain open, allowing the inventory to discharge until manual action was taken.
Personnel attempting manual isolation inside an active ammonia cloud without specialized PPE points to a breakdown in transfer training and immediate site-level emergency response execution.
Potentially Applicable Standards
ANSI/CGA G-2.1 (Requirements for the Storage and Handling of Anhydrous Ammonia)
ANSI/CGA G-2.1 establishes recognized engineering designs and administrative practices for anhydrous ammonia systems:
Emergency Shutoff Valves (ESVs) and Check Valves: Requires bulk liquid and vapor transfer lines to feature positive shutoff valves paired with internal back-pressure check valves or excess flow valves. It mandates emergency shutoff valves capable of remote actuation. This design allows operators to halt uncontrolled flow from a safe distance without entering the vapor plume.
Transfer Hose Specifications: Details design burst pressures, scheduled hydrostatic testing intervals, and replacement criteria to minimize the likelihood of hose ruptures under normal operating stress.
Operating and Emergency Procedures : Specifies mandatory protective equipment (including respiratory protection and impervious suits) for handling leaks, while requiring formal training every three years to instruct personnel against entering toxic atmospheres without proper life-support apparatus.
Top Three Information Sources
Bluefield Process Safety: "In the News: An Ammonia Release in Troy" (September 10, 2026).
Lincoln CountyWatch: "Anhydrous Ammonia Leak Prompts Evacuations, State of Emergency in Troy" (September 4, 2026).
KSDK News: "State of emergency issued in Troy, Missouri, after anhydrous ammonia leak" (September 4, 2026).